Question

QUESTION 1

Select the correct statement regarding Signal-to-Noise Ratio (aka SNR or S/N).

		a. The SNR should be kept as low as possible to ensure reception
		b. The 'Noise" in the SNR equation is predominated by "thermal noise" which cannot be eliminated
		c. SNR is only critical for satellite communications where great distances exist between transceivers. Normal terrestrial communication links do not need to consider SNR.
		d. SNR is only used when transmitting analog voice signals

    

QUESTION 2

Antenna Gain describes the ratio of a directional antenna over that of an isotropic antenna in the desired transmitting direction (i.e., maximum power direction). It is typically represented in the decibel form referenced to the ideal isotropic antenna (i.e., dBi)

True

False

    

QUESTION 3

Determine the Free Space Loss (FSL=(4πd/λ)²) in decibels, between two transceivers given the following: d=100km, f=5GHz.

		a. [FSL] = 148.00 dB
		b. [FSL] = 131.98 dB
		c. [FSL] = 241.98 dB
		d. [FSL] = 121.98 dB

Answer 1

1.

The SNR should be kept as low as possible to ensure reception.

Option 1

2.

Antenna Gain describes the ratio of a directional antenna over that of an isotropic antenna in the desired transmitting direction (i.e., maximum power direction). It is typically represented in the decibel form referenced to the ideal isotropic antenna (i.e., dBi)

True

3.

From the question:

d=100 km, f=5 GHz.

Free Space Loss in Db = 20 log f + 20 log d +92.4

Substitute the corresponding values in the above formula.

= 20 log 100 + 20 log 5 +92.4

= 146.3794

Options not contain correct value. Just follow this formula for dB.

FSL=(4πd/λ)² formula does not give dB FSL.